One-way explosive connector device



June 20, 1967 M. L SCHIMMEL ONE-WAY EXPLOSIVE CONNECTOR DEVICE Filed Feb. '7, 1966 United States Patent O 3,326,127 UNE-WAY EXPLOSIVE CONNECTOR DEVICE Merry L. Schimmel, University City, Mo., assigner to McDonnell Aircraft Corporation, St. Louis, Mo., a corporation of Maryland Filed Feb. 7, 1966, Ser. No. 525,570 Claims. (Cl. 102-27) This invention relates to one-way explosive connectors and is especially concerned lwith improvements in such connectors whereby the detonation wave will travel in one direction only and be prevented from taking effect in the opposite or in an undesired direction.

While the present device has a range of useful applications, it may be understood in connection with an explosive assembly for effecting separation of the crew capsule of aircraft Where rapid separation of the capsule must be carried out in a predictable manner for the `safety of the crew. The problem in effecting release of crew capsules is to initiate the detonation wave in a desired direction and in a predetermined sequence because of surrounding structure limitations and other factors. What has been needed is a simple device of compact construction which does not require the usual internal elements, such as tiring pins, shear pins, seals, and complicated explosive trains. When such internal components are eliminated, the result is an inert connector which is not subject to the usual service life 'restrictions required for pyrotechnic devices. It is recognized that prior internal explosive charge devices are the weak link in high speed disconnector systems because of temperature vulnerability.

It is an important object of this invention to provide an explosive device for controlling severance of recoverable apparatus and object and to embody simple detonation means which relies upon the formation of high velocity shrapnel rather than shock wave generation by the primary means to initiate the propagation of detonation in a predetermined direction.

An important further object of this invention is to provide a one-way explosive connector device which improves on prior devices and gives assurance of being effective in only one predetermined direction.

It is another important object of this invention to provide an improved explosive connector device that will positively initiate an explosive detonating wave in one direction and inhibit reverse waves or energy transfer.

It is also an object of this invention to provide an improved explosive connector device in which one or more high velocity shrapnel producing explosive donor means are arranged in angular relation to an explosive acceptor means such that only when the shrapnel from the explosive donor means is directed against the acceptor means will detonation of the acceptor be initiated, and should the explosive acceptor means be detonated, the resulting shrapnel will not strike the donor means, thereby preserving the predetermined sequence of detonation propagation.

Other objects and advantages of the invention are to be found in the parts, components and arrangement thereof, all as set forth in certain preferred embodiments which are illustrated in the accompanying drawings, wherein:

FIG. l is an assembly view of the explosive connector device in one preferred embodiment;

FIG. 2 is a sectional view on an enlarged scale of the device in FIG. 1 as seen at line 2-2 therein;

FIG. 3 is a sectional view of a modied device; and

FIG. 4 is a sectional view of a typical explosive means incorporated in the devices illustrated herein.

Referring to FIGS. l and 2, the one-way explosive connector device 5 comprises a physically compact body 6 formed with a rst bore 7 having a threaded port 8 CII opening outwardly at one end, and a second bore 9 having a threaded port 10 opening outwardly at the end opposite the port 8. The bore 7 has it longitudinal axis directed at an angle A to the longitudinal axis of bore 9, thereby forming a recess 11 off-set from the bore 7 but directly in axial alignment with bore 9. The threaded port 8 receives an explosive donor means 12, and the threaded port 10 receives an explosive acceptor means 13.

The explosive donor means 12 and explosive acceptor means 13 are of the same design, and reference will now be made to FIG. 4 where the internal construction of means 12 has been disclosed. Where applicable similar reference numerals will apply to both means. Thus, means 12 includes a body 14 having threads 15 on its inner end and a tool head 16 at its outer end by which it is threaded into position in body 6. The body 14 is formed with a bore 17 and a counter bore 18. A ferrule 19 has an inwardly elongated extension 20 which is securely connected to the end portion 21 of a tube 22 by the circumferential crimps C. The ferrule 19 is formed with a projecting ferrule tip 23 to receive a cap 24 of shrapnel forming material. The cap 24 houses a body of explosive 25 in compact relation to an explosive 26 which is packed into the ferrule tip 23. The explosive train 26 extends through the bore 27 in ferrule 19 in the form of a detonating cord 28. The cord 28 is securely mounted in the body 14 within the extension 2t) and extends outwardly where it is confined within the tube 22. A body 29 of vibration damping material lls the space between the cord 28 and tube 22. It has been pointed out that the explosive donor means 12 and the explosive acceptor means 13 are made up of similar components which have been described in connection with the disclosure of FIG. 4. Gaskets G are used to seal the heads 16 of these means upon threadedly mounting the same in the ports 8 and 1t) of body 6.

The operation of the device 5 shown in FIG. 2 is such that upon initiation of the explosive charge of cord 28 in donor means 12, the cap 24 is fragmented and the resulting particles form shrapnel which moves at high velocity through the length of bore 7 directly at the cap 24 of the acceptor means 13 with sufficient impact to cause detonation of the explosive charge in the cap 24 of means 13. This causes the explosive sequence to travel from right to left, as seen in FIG. 2. On the other hand, should the acceptor means 13 ne detonated first, the high velocity shrapnel resulting from rupture of its cap 24 will travel in bore 9 and be dissipated in the recess 11 so that the cap 24 of donor means 12 will not be hit. The action is similar to a check valve in a hydraulic system where the flow of pressure fluid is limited to one direction and prevented from acting in the reverse direction.

In FIG. 3, the modified device 30 includes a body having portions 31 and '32 arranged at right angles, Iand a portion 33 arranged at an angle B to the axis of the body portion 32. As shown, body portion 31 has an axial bore 34 open to the axial Ibore 35 of body portion 32 in a right angular or T relation, but the bore 36 in body portion 33 is directed angularly relative to bore 35 to end in recess 37. Each body portion mounts an explosive means similar iu construction to that disclosed in FIG. 4. For the sake of clarity, the means in body portions 31 and '32 are denominated donor means 38a and 3811 respectively, while the means in body portion 33 is denominated acceptor means 38C.

In operation, initiation of the explosive charge in donor means 38a will cause rupture of its cap 24, releasing a high velocity shrapnel charge directly at cap 24 of donor means 38h. Donor means 38h will be detonated to release a high velocity shrapnel charge through `bore 35 directly -at acceptor means 38C, which will be detonated. Should acceptor means 38C be detonated first, the resulting high velocity shrapnel charge will be dissipated in the recess 37 and not detonate donor means 38k. This action will therefore protect both donor means 38a and 3811, thereby protecting the explosive cords of these latter means and preventing reversal of the action. Should donor means 38b detonate rst, the cap 24 will fragment into axial shrapnel and lateral shrapnel charges, the axial shrapnel detonating acceptor means 38C and the lateral shrapnel detonating donor means 38a.

In the detonating means of FIG. 4, it has been found on tests that gilding metal or stainless steel for the cap 24 is superior to forming the cap from aluminum, electrolytic copper or non-metallic materials. The superiority is attributed to a more concentrated and reproducible pattern of the shrapnel upon sudden fragmentation of the cap 24. It has also been found by test that fragmentation of the cap 24 forms effective shrapnel charges in two directions; one being the body of fragments formed by the end wall 24a of the cap, and the other being the body of fragments thrown out by the side wall 24b of the cap. The preferred end and side wall thickness for the cap 24 is 0.004 inch. For short axial distances, the fragments from end wall 24a will remain in a tight body having a narrow angle of spread, thereby producing a substantial concentration of extremely high velocity shrapnel. Over a distance of several inches the initial velocity of the order of about 9500 feet per second will decay relatively slightly to the order of somewhat less than 9000 feet per second. In lateral fragmentation, the cap side wall 24b will fracture into shrapnel particles having an initial velocity of the order of 7600 feet per second, and in several inches of travel the velocity will decay to the order of about 7000 feet per second. The explosive charge 26 in these tests consisted of secondary high explosives similar to RDX. These charges `are relatively insensitive to heat and vibration and therefore require a sudden and high velocity shock accompanied by pressure behind the shock front. This shock and pressure is imparted to the acceptor by the 4impact of high velocity donor shrapnel.

As compactness of body 6 is a desired objective herein, it has been determined, with caps 24 of 0.156 inch diameter con-taining 65 milligrams of output charge, that effective angular relations can vary between 10 and 60. Thus angle A or B can have this variation when the linear distance between centers of the caps 24 is adjusted so that the cap 24 of donor means 12 is just clear of the axially directed cone of flight of the shrapnel from the donor cop 24 of acceptor means 13 when initiated in the no-re direction. The relation of angle A or B to distance between donor and acceptor caps 24 is such that for an angle of about 10 the distance required is about 1.9 0 inches, and for an angle of about 60 the distance can be reduced to about 0.25 inch. These physical characteristics will provide a no-detonation safety factor of 2, thereby assuring one-way detonation propagation. A preferred angular relation is about 30 for angle A and B shown in FIGS. 2 and 3, with a distance of 0.65 inch.

While certain preferred embodiments of this invention have been shown and described, it is understood that modications may be made within the area of the diS- elosure and the scope of the appended claims.

What is claimed is:

1. A one-way explosive connector device for joining two lengths of detonating cord comprising a body having spaced ports opening into bores which extend into said body and intersect therewithin, the axis of the bore ex tending from a first port being -at an angle to the axis of the bore extending from a second port, an explosive acceptor means connected at its outermost end to one detonating cord and mounted in the first port, said acceptor means having a shrapnel forming cap at its innermost end in line with the bore from said second port, an explosive donor means connected at its -outermost end to the other detonating cord and mounted in the second port, said donor means having -a shrapnel forming cap at its innermost end positioned in the bore open-ing t0 said second port, and said body having a recess formed at one side of the bore opening to said second port, said recess being an axial extension of the bore opening to said first port, said bores and recess being related such that detonation of said donor cap will release shrapnel into said bore from the second port to detonate said acceptor cap and detonation of said acceptor cap will release shrapnel into said bore from said rst port to dissipate in said recess.

2. The device set forth in claim 1, wherein said angle between the axes of said bores yis of the order of 10 to 60 degrees, and said acceptor and donor caps are spaced apart such that as said angle decreases the spacing between said caps increases.

3. The device set forth in `claim 1, wherein said donor cap has end and side walls, the end wall upon detonation fragmenting and constituting a body of shrapnel to travel through said bore from said second port and detonate said acceptor cap.

4. The device set forth vin claim 1, and including a lthird detonating cord, an additional port opening into a bore which intersects with the bore from said second port, an additional explosive donor means connected at its outermost end to said third detonating cord and mounted in said additional port, and a shrapnel forming cap carried by said additional donor means at the innermost end thereof, said shrapnel forming cap carried by said additional explosive donor means being aligned with said rst mentioned donor means shrapnel forming cap, whereby detonation of either said donor means or said additional donor means will effect detonation of said acceptor means.

5. A connector device for joining detonator cords and permitting detonation of the cords in only one direction, said device comprising: a body formed with spaced ports opening inwardly into bores, the bore from one port intersecting the bore from a second port and terminating in a recess off-set from said second port; explosive members mounted in said ports; means connecting said explosive members to the detonator cords; and shrapnel forming caps carried by said members within said bores, the cap carried by said member in said second port having a shrapnel forming wall facing the cap carried by said member in said one port, and the cap carried by said member in said one port having a shrapnel forming wall facing said off-set recess, where-by only detonation of said explosive member in said second port will fragment said shrapnel forming wall and detonate said cap carried by the member mounted in said one port.

No references cited.

SAMUEL W. ENGLE, Primary Examiner. 

1. A ONE-WAY EXPLOSIVE CONNECTOR DEVICE FOR JOINING TWO LENGTH OF DETONATING CORD COMPRISING A BODY HAVING SPACED PORTS OPENING INTO BORES WHICH EXTEND INTO SAID BODY AND INTERSECT THEREWITHIN, THE AXIS OF THE BORE EXTENDING FROM A FIRST PORT BEING AT AN ANGLE TO THE AXIS OF THE BORE EXTENDING FROM A SECOND PORT, AN EXPLOSIVE ACCEPTOR MEANS CONNECTED AT ITS OUTERMOST END TO ONE DETONATING CORD AND MOUNTED IN THE FIRST PORT, SAID ACCEPTOR MEANS HAVNG A SHRAPNEL FORMING CAP AT ITS INNERMOST END IN LINE WITH THE BORE FROM SAID SECOND PORT, AN EXPLOSIVE DONOR MEANS CONNECTED AT ITS OUTERMOST END TO THE OTHER DETONATING CORD AND MOUNTED IN THE SECOND PORT, SAID DONOR MEANS HAVING A SHRAPNEL FORMING CAP AT ITS INNERMOST END POSITIONED IN THE BORE OPENING TO SAID SECOND PORT, AND SAID BODY HAVING A RECESS FORMED AT ONE SIDE OF THE BORE OPENING TO SAID SECOND PORT, SAID RECESS BEING AN AXIAL EXTENSION OF THE BORE OPENING TO SAID FIRST PORT, SAID BORES AND RECESS BEING RELATED SUCH THAT DETONATION OF SAID DONOR CAP WILL RELEASE SHRAPNEL INTO SAID BORE FROM THE SECOND PORT TO DETONATE SAID ACCEPTOR CAP AND DETONATION OF SAID ACCEPTOR CAP WILL RELEAST SHRAPNEL INTO SAID BORE FROM SAID FIRST PORT DISSIPLATE IN SAID RECESS. 